Epoxy-containing dental composition curable by multiple polymerization mechanisms

ABSTRACT

Polymerizable compositions are provided that contain an epoxy compound and a polymerizable, ethylenically-unsaturated resin having an acid functional group where the epoxy compound is polymerized by cationic polymerization initiated by the acid functional group and the polymerizable, ethylenically-unsaturated resin is polymerized by free-radical polymerization. To that end, a two-part polymerizable composition is provided that has a first part containing the epoxy compound; and a second part containing the polymerizable, ethylenically-unsaturated resin having an acid functional group. The first part and/or the second part further contain a radical initiator effective to initiate either self-curing or light-curing by free-radical polymerization.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 37 C.F.R. §1.78(a)(4), this application claims the benefitof and priority to prior filed co-pending Provisional Application Ser.No. 61/186,063, filed Jun. 11, 2009, which is expressly incorporatedherein by reference.

FIELD OF INVENTION

The present invention relates to adhesive and/or sealant compositionsthat cure by cationic polymerization and free-radical polymerization,and particularly to self-adhering dental compositions suitable for useas a root canal sealer.

BACKGROUND OF INVENTION

Methacrylate resin-based compositions have been used in dentistry fordecades. However, dental materials based on (meth)acrylate resins, whichare chemically cured, usually have wet surfaces due to the inhibition ofthe free-radical polymerization reaction at the surface by molecularoxygen. The oxygen inhibition is even more apparent as the rate ofpolymerization of the material decreases. This presents a potentialproblem with the restoration of a tooth. For example, when the oxygeninhibition effect takes place in an interface, such as at the toothsurface of a root canal, unsatisfactory sealing may result.

Alternatively, compositions cured by epoxy ring-opening polymerizationhave been used to seal root canals. For example, products, such as AH26® Silver Free and AH PLUS JET® by Dentsply, arecommercially-available, two-part epoxy-amine compositions. Whilecompositions cured by epoxy ring-opening polymerization are notsusceptible to the oxygen inhibition effect, as described above, twodrawbacks to these conventional epoxy and amine two-component systemsare slower reaction times at room temperature, and lack of adhesion to atooth surface. Additionally, the slow curing time inhibits the materialfrom possessing instant mechanical properties because the setting timeof the material can take hours, if not days.

Compositions cured by epoxy ring-opening polymerization may also beinitiated through a cationic polymerization of the epoxy resin using astarter, such as a Lewis acid or a strong Brønsted acid. For example,Lewis acids, such as BF₃.Et₂O, BF₃.THF, AlCl₃, FeCl₃ and the like, whereEt₂O is diethyl ether and THF is tetrahydrofuran, may initiate thecationic ring-opening polymerization under ambient conditions.Similarly, strong Brønsted acids, such as HBF₄, HB(C₆F₅)₄, HPF₆, HAsF₆or HSbF₆ may initiate the cationic ring-opening polymerizationimmediately after mixing with the epoxy.

Another type of initiator for the cationic ring-opening polymerizationis a latent starter, which upon contact with the epoxy does not itselfinitiate the polymerization, but starts the polymerization upon contactwith an agent that transforms the starter into a form that is able toinitiate the polymerization. For example, halonium salts of the generalformula Hal-(Ar)₂ ⁺An⁻, wherein Hal is a halogen, Ar is an aryl group,and An is an anion, when transformed can liberate H⁺ as extremely strongacid H⁺An⁻. An exemplary latent starter is diaryliodonium compounds,such as diphenyliodonium tetrafluoroborate, diphenyliodoniumhexafluorophosphate and the like. Generally, Cu(I) salts and a reducingagent, such as ascorbic acid, are used to transform the halonium salt.

Additionally, the use of light-initiated cationic ring-openingpolymerization of epoxy resins in dentistry has grown in recent years,largely due to the lower shrinkage of the resulting composite ascompared to the free radical polymerization of (meth)acrylates. Butthese epoxy compositions cured by the methods described above can stillpresent poor adhesion to a tooth surface.

Therefore, what is needed is a composition that possesses favorablecuring properties and improved adhesion.

SUMMARY OF THE INVENTION

In one embodiment of the invention, a polymerizable composition isprovided comprising a first part comprising an epoxy compound; and asecond part comprising a polymerizable, ethylenically-unsaturated resinhaving an acid functional group, wherein the first part and/or thesecond part further comprises a radical initiator.

In another embodiment of the invention, a method of providing apolymerized composition is provided which comprises mixing a first partcomprising an epoxy compound with a second part comprising apolymerizable, ethylenically-unsaturated resin having an acid functionalgroup, wherein the mixing initiates a cationic polymerization reactionof the epoxy compound facilitated by the acid functional group; andpolymerizing the polymerizable, ethylenically-unsaturated resin, whereinthe polymerizing is a free-radical polymerization initiated by aself-cure free-radical initiator and/or an photo-initiated free radicalinitiator.

In another embodiment of the invention, a method of curing a two-partcomposition, which has a first part comprising an epoxy compound, and asecond part comprising a polymerizable, ethylenically-unsaturated resinhaving an acid functional group, wherein the first and/or second partfurther comprises a self-cure free-radical initiator and/or aphoto-initiated free-radical initiator, is provided wherein the methodcomprises effecting a first polymerization of the epoxy compoundinitiated by the acid functional group selected from the groupconsisting of a carboxylic acid, a carboxylic acid anhydride, an acylhalide, a sulfonic acid, a sulfonic anhydride, a sulfonyl halide, asulfinic acid, a sulfinic anhydride, a sulfinyl halide, a phosphoricacid, a phosphoric acid derivative, a phosphonic acid, and a phosphonicacid derivative; and effecting a second polymerization of thepolymerizable, ethylenically-unsaturated resin initiated by theself-cure free radical initiator and/or the photo-initiated free radicalinitiator.

In another embodiment of the invention, a kit is provided comprising afirst part comprising an epoxy compound; a second part comprising apolymerizable, ethylenically-unsaturated resin having an acid functionalgroup, wherein the first and/or second part further comprises a radicalinitiator, wherein the first part and the second part are provided inpackaging that physically separates the first part from the second part;and instructions for mixing to effect a self-cure.

In yet another embodiment of the invention, there is provided a methodof providing a polymerizable composition comprising providing a firstpart comprising an epoxy compound; and providing a second partcomprising a polymerizable, ethylenically-unsaturated resin having anacid functional group, wherein the first and/or second part furthercomprises a self-cure free-radical initiator and/or a photo-initiatorfree-radical initiator, whereby upon mixing the first part and thesecond part the acid functional group is adapted to initiate a cationicpolymerization of the epoxy compound; and the self-cure free-radicalinitiator and/or a photo-initiator free-radical initiator is adapted toinitiate a free-radical polymerization of the polymerizable,ethylenically-unsaturated resin.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is related to a two-part polymerizable compositionhaving improved adhesion or bond strength to a substrate. In oneexemplary embodiment, a two-part paste/paste acidic self-adhering dentalcomposition is provided, wherein the first part comprises an epoxycompound and the second part comprises a polymerizable,ethylenically-unsaturated resin having an acid functional group and thefirst part and/or the second part further comprises a radical initiator.

According to one embodiment of the invention, a self-adhesive two-partpaste/paste dental composition is prepared for use by mixing together anepoxy compound and a polymerizable, ethylenically-unsaturated resinhaving an acid functional group, along with a radical initiator. Thiscombination provides for two modes of cure for the resinous combination:epoxy ring-opening polymerization catalyzed by the acidic functionalgroup and free-radical polymerization of the ethylene moieties.

As used herein, the term “self-cure” means the inventive compositionscan go through a chemical polymerization process when the first part andthe second part are mixed together, without an external energy such asheat, light, or other radiation energies. For example, the epoxy-ringopening polymerization through the cationic reaction of the epoxy andacid group contained in the polymerizable monomer and/or through a redoxreaction of a peroxide-tertiary amine initiated free radical curing forthe (meth)acrylate monomer(s) in the compositions. The sequence of thevarious polymerization mechanisms can be simultaneous, sequential, oreven delayed with respect to the other(s).

The first part of the two-part polymerizable composition may compriseepoxy resins of many different structures. These epoxy resins includemonomeric epoxy compounds and epoxides of the polymeric type and may bealiphatic, cycloaliphatic, aromatic or heterocyclic. These epoxy resinsgenerally have, on the average, about one polymerizable epoxy group permolecule, but may include about two polymerizable epoxy groups permolecule. The polymeric epoxides include linear polymers having terminalepoxy groups (e.g., a diglycidyl ether of a polyoxyalkylene glycol),polymers having skeletal oxirane units (e.g., polybutadienepolyepoxide), and polymers having pendent epoxy groups (e.g., a glycidylmethacrylate polymer or copolymer). The epoxides may be pure compoundsor may be mixtures of compounds containing one, two, or more epoxygroups per molecule. The “average” number of epoxy groups per moleculeis determined by dividing the total number of epoxy groups in theepoxy-containing material by the total number of epoxy-containingmolecules present.

These epoxy-containing materials may vary from low molecular weightmonomeric materials to high molecular weight polymers and may varygreatly in the nature of their backbone and substituent groups.Illustrative of permissible substituent groups include halogens, estergroups, ethers, sulfonate groups, siloxane groups, nitro groups,phosphate groups, and the like. The molecular weight of theepoxy-containing materials may vary from about 58 to about 100,000 ormore.

Useful epoxy-containing materials include those which containcyclohexane oxide groups such as epoxycyclohexane carboxylates, typifiedby 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate,3,4-epoxy-2-methylcyclohexylmethyl-3,4-epoxy-2-methylcyclohexanecarboxylate, and bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate.

Other epoxy-containing materials that are useful in this inventioninclude glycidyl ether monomers, such as glycidyl ethers of polyhydricphenols obtained by reacting a polyhydric phenol with an excess ofchlorohydrin such as epichlorohydrin (e.g., the diglycidyl ether of2,2-bis-(2,3-epoxypropoxyphenol)-propane).

Still other epoxy resins contain copolymers of acrylic acid esters orglycidol such as glycidylacrylate and glycidylmethacrylate with one ormore copolymerizable vinyl compounds. Examples of such copolymers are1:1 styrene-glycidylmethacrylate, 1:1methylmethacrylate-glycidylacrylate and a 62.5:24:13.5methylmethacrylate-ethyl acrylate-glycidylmethacrylate.

Other useful epoxy resins are well known and contain epoxides, such asepichlorohydrins; alkylene oxides, e.g., propylene oxide; styrene oxide;alkenyl oxides, e.g., butadiene oxide; and glycidyl esters, e.g., ethylglycidate.

Blends of various epoxy-containing materials are also contemplated.Examples of such blends include two or more weight average molecularweight distributions of epoxy-containing compounds, such as lowmolecular weight (below 200), intermediate molecular weight (200 to10,000) and high molecular weight (above 10,000). Alternatively oradditionally, the epoxy resin may contain a blend of epoxy-containingmaterials having different chemical natures, such as aliphatic andaromatic, or different functionalities, such as polar and non-polar.

There are a host of commercially-available epoxy resins which can beused in this invention. In particular, epoxides which are readilyavailable include octadecylene oxide, epichlorohydrin, styrene oxide,vinylcyclohexene oxide, glycidol, glycidyl methacrylate, diglycidylether of Bisphenol A (e.g., those available under the trade designations“Epon 828”, “Epon 825”, “Epon 1004” and “Epon 1010” from Shell ChemicalCo., “DER-331”, “DER-332”, and “DER-334”, from Dow Chemical Co.),vinylcyclohexene dioxide (e.g., “ERL-4206” from Union Carbide Corp.),3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexene carboxylate (e.g.,“ERL-4221” or “CYRACURE UVR 6110” or “UVR 6105” from Union CarbideCorp.),3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methyl-cyclohexenecarboxylate (e.g., “ERL-4201” from Union Carbide Corp.),bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate (e.g., “ERL-4289” fromUnion Carbide Corp.), bis(2,3-epoxycyclopentyl)ether (e.g., “ERL-0400”from Union Carbide Corp.), aliphatic epoxy modified from polypropyleneglycol (e.g., “ERL-4050” and “ERL-4052” from Union Carbide Corp.),dipentene dioxide (e.g., “ERL-4269” from Union Carbide Corp.),epoxidized polybutadiene (e.g., “Oxiron 2001” from FMC Corp.), siliconeresin containing epoxy functionality, flame retardant epoxy resins(e.g., “DER-580”, a brominated bisphenol type epoxy resin available fromDow Chemical Co.), 1,4-butanediol diglycidyl ether of phenolformaldehydenovolak (e.g., “DEN-431” and “DEN-438” from Dow Chemical Co.),resorcinol diglycidyl ether (e.g., “Kopoxite” from Koppers Company,Inc.), bis(3,4-epoxycyclohexyl)adipate (e.g., “ERL-4299” or “UVR-6128”,from Union Carbide Corp.),2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-meta-dioxane(e.g., “ERL-4234” from Union Carbide Corp.), vinylcyclohexene monoxide1,2-epoxyhexadecane (e.g., “UVR-6216” from Union Carbide Corp.), alkylglycidyl ethers such as alkyl C₈-C₁₀ glycidyl ether (e.g., “HELOXYModifier 7” from Shell Chemical Co.), alkyl C₁₂-C₁₄ glycidyl ether(e.g., “HELOXY Modifier 8” from Shell Chemical Co.), butyl glycidylether (e.g., “HELOXY Modifier 61” from Shell Chemical Co.), cresylglycidyl ether (e.g., “HELOXY Modifier 62” from Shell Chemical Co.),p-ter butylphenyl glycidyl ether (e.g., “HELOXY Modifier 65” from ShellChemical Co.), polyfunctional glycidyl ethers such as diglycidyl etherof 1,4-butanediol (e.g., “HELOXY Modifier 67” from Shell Chemical Co.),diglycidyl ether of neopentyl glycol (e.g., “HELOXY Modifier 68” fromShell Chemical Co.), diglycidyl ether of cyclohexanedimethanol (e.g.,“HELOXY Modifier 107” from Shell Chemical Co.), trimethylol ethanetriglycidyl ether (e.g., “HELOXY Modifier 44” from Shell Chemical Co.),trimethylol propane triglycidyl ether (e.g., “HELOXY Modifier 48” fromShell Chemical Co.), polyglycidyl ether of an aliphatic polyol (e.g.,“HELOXY Modifier 84” from Shell Chemical Co.), polyglycol diepoxide(e.g., “HELOXY Modifier 32” from Shell Chemical Co.), bisphenol Fepoxides (e.g., “EPN-1138” or “GY-281” from Ciba-Geigy Corp.), and9,9-bis[4-(2,3-epoxypropoxy)-phenyl]fluorenone (e.g., “Epon 1079” fromShell Chemical Co.).

Additionally, the epoxy resin may be accompanied by a variety of otherresins, including free radically-polymerizable resins,ionically-polymerizable resins, or combinations thereof, provided thatthe resins do not contain an acid functional group. Examples of freeradically-polymerizable resins include, but are not limited to thoseresins with ethylenically unsaturated functional groups, such as(meth)acrylates; vinyl monomers, such as styrene; vinyl esters; and avariety of unsaturated cyclic monomers, such as spiro-ortho carbonates,spiro-ortho esters, vinyl cyclic ethers, and cyclic acetals.

Examples of ionically-polymerizable resins include, but are not limitedto, vinyl ethers; and cyclic monomers, such as epoxies, siloranes,lactides, ε-caprolactones, and ε-caprolactams.

Examples of resins containing both free radically- and ionically-activefunctional groups include, but are not limited to, the resin oligomershaving both an epoxy functionality and a (meth)acrylate functionality asset forth in commonly owned U.S. Pat. No. 7,241,856, which is herebyincorporated by reference.

Examples of ethylenically-unsaturated resins include those based onacrylate and methacrylate monomers, for example those disclosed in U.S.Pat. Nos. 3,066,112, 3,179,623, and 3,194,784 to Bowen; U.S. Pat. Nos.3,751,399 and 3,926,906 to Lee et al.; and commonly assigned U.S. Pat.No. 5,276,068 to Waknine, all of which are herein incorporated byreference in their entirety. Methacrylate-based monomers areparticularly useful, including the condensation product of bisphenol Aand glycidyl methacrylate; 2,2′-bis[4-(3-methacryloxy-2-hydroxypropoxy)-phenyl]-propane (BIS-GMA); dipentaerythritol pentaacrylate(DPEPA); pentaerythritol dimethacrylate (PEDM); the condensation productof ethoxylated bisphenol A and glycidyl methacrylate (EBPA-DMA);urethane dimethacrylate (UDMA); ethoxylated bisphenol Adi(meth)acrylates including ethoxylated bisphenol A dimethacrylate(EBPDMA) as disclosed in U.S. Pat. No. 6,013,694 to Jia, et al.; thecondensation product of 2 parts hydroxymethylmethacrylate and 1 parttriethylene glycol bis(chloroformate) (PCDMA); polyurethane-baseddimethacrylates (PUDMA) and polycarbonate modified-BisGMA (PCBisGMA) andother monomers set forth in commonly owned U.S. Pat. No. 6,787,629,which is hereby incorporated by reference.

This first part may also contain other additives, such as radiopaque andthickening fillers. Additionally, free radical initiator systems thatare compatible with an epoxide functional group may also be included.For example, light initiators, such as camphorquinone (CQ); andco-initiators, such as ethyl-4-dimethyl benzoate (EDMAB); areparticularly suitable for use. Self-cure initiators as reducing agentsfor the free-radical polymerization of methacrylates, such asbis(2-hydroxylethyl)-p-toluidine (DHEPT), dimethyl-p-toluidine (DMPT),and thioureas, may also be included. The commonly-known epoxy additionreaction polymerization initiators, such as a primary or a secondaryamine should not be included.

The second part of the multi-part polymerizable composition, whichcomprises a polymerizable, ethylenically-unsaturated resin having anacid functional group, includes aliphatic or aromatic polymerizableresin monomers or oligomers. It is generally understood that the acidfunctional group facilitates the self-etching or self-adhering effect tothe tooth structure, as well as acts as an initiator of the epoxypolymerization reaction. Furthermore, in one embodiment, an ionicreaction between the acid group of the ethylenically-unsaturated resinand the surface of an acid-reactive glass ionomer filler is alsopossible when there is water/moisture present.

These polymerizable monomers or oligomers comprise at least one acidicfunctional group, which includes acid-precursor functional groups, suchas anhydrides. For example, an anhydride may react with water, analcohol or the like to form a carboxylic acid. As such, an acidicfunctional group may be a carboxylic acid, carboxylic acid anhydride,acyl halide, sulfonic acid, sulfonyl halide, sulfonic anhydride,sulfinic acid, sulfinyl halide, sulfinic anhydride, phosphoric acid,phosphoric acid derivative, phosphonic acid, and phosphonic acidderivative, and combinations thereof. Additionally, the polymerizablemonomers or oligomers comprise at least one polymerizable unsaturatedcarbon-carbon bond, such as an alkene functional group. In oneembodiment, the polymerizable, ethylenically-unsaturated resin is anethylenically-unsaturated carboxylic acid.

In another embodiment, the polymerizable, ethylenically-unsaturatedresin contains at least two acidic functional groups. For example, theratio between the number of acidic functional groups and the number ofpolymerizable unsaturated carbon-carbon bonds in the polymerizable,ethylenically-unsaturated resin may range between about 1:3 to about3:1, for example, about 1:2 to about 2:1.

Exemplary polymerizable, ethylenically-unsaturated resins include, butare not limited to, acrylic acid, methacrylic acid,2-(methacryloyloxy)ethyl phosphate,bis(2-(methacryloyloxy)ethyl)phosphate, biphenyl dimethacrylate,ethylene glycol methacrylate phosphate, 4-methacryloxyethyl trimelliticanhydride, 4-methacryloxyethyl trimellitic acid, adduct reaction productof pyromellitic di-anhydride with 2-hydroxyethylmethacrylate, adductreaction product of pyromellitic di-anhydride with glyceroldimethacrylate, or adduct reaction product of benzenetetracarboxylicacid di-anhydride with 2-(6-hydroxy-1-oxo-hexyloxy)ethyl methacrylate.

Another suitable class of polymerizable, ethylenically-unsaturatedresins is an ethylenically-unsaturated phosphoric acid ester having thegeneral formula:

(CH₂═C(CH₃)CO₂—R—O)_(n)P(O)(OH)_(3-n)

wherein R is a substituted or un-substituted alkyl or aryl group havingabout 1 to about 36 carbon atoms and n equals 1 or 2.

Additionally, the second part may further include a variety of otherresins that do not have an acid functional group, including freeradically-polymerizable resins, ionically-polymerizable resins, orcombinations thereof, as discussed above, provided that the resin isstable under reasonable storage conditions in the presence of an acidfunctional group and the other constituents included in this mixture.The second part may also contain other additives, such as radiopaque andthickening fillers. Self-cure initiators compatible with the acidicmedia may also be included. For example, oxidizing agents such asbenzoyl peroxide or cumene hydroperoxide are suitable for use.

Known viscous resins may be added to the first part or the second partof the polymerizable composition. Non-limiting examples includepolyurethane dimethacrylates (PUDMA), diurethane dimethacrylates(DUDMA), and/or the polycarbonate dimethacrylate (PCDMA) disclosed inU.S. Pat. Nos. 5,276,068 and 5,444,104 to Waknine, which is thecondensation product of two parts of a hydroxyalkylmethacrylate and 1part of a bis(chloroformate). Another advantageous resin having lowerwater sorption characteristics is an ethoxylated bisphenol Adimethacrylate (EBPDMA) as disclosed in U.S. Pat. No. 6,013,694. Anespecially useful methacrylate resin is the condensation product ofbisphenol A and glycidyl methacrylate,2,2′-bis[4-(3-methacryloxy-2-hydroxy propoxy)-phenyl]-propane (Bis-GMA).

Diluent monomers may be added to the first part or the second part ofthe polymerizable composition to increase the surface wettability of thecomposition and/or to decrease the viscosity of the polymerizationmedium. Suitable diluent monomers include those known in the art such ashydroxy alkyl methacrylates, for example 2-hydroxyethyl methacrylate and2-hydroxypropyl methacrylate; ethylene glycol methacrylates, includingethylene glycol methacrylate, diethylene glycol methacrylate,tri(ethylene glycol)dimethacrylate and tetra(ethyleneglycol)dimethacrylate; and diol dimethacrylates such asbutanedimethacrylate, dodecanedimethacrylate, or1,6-hexanedioldimethacrylate (HDDMA). Tri(ethylene glycol)dimethacrylate(TEGDMA) is particularly suitable for use.

Diluent monomers or viscous resins, when present, are incorporated intothe polymerizable composition in an amount of about 1 to about 70 wt %of the total composition. Optionally, excess water or alcohol may beincluded.

As stated above, the composition further includes a radicalpolymerization curing system to facilitate another mechanism for curingthe polymerizable resins. These initiator systems may includepolymerization initiators; polymerization accelerators; ultravioletlight absorbers; antioxidants; and other additives known in the art.

A light cure system may be selected from known light-activatedpolymerization initiators, including but not being limited to benzil,benzoin, benzoin methyl ether, DL-camphorquinone (CQ) and benzildiketones. Either UV-activated cure or visible light-activated cure(about 230 nm to about 750 nm) is acceptable. The amount ofphotoinitiator may be selected according to the curing rate desired. Aminimally catalytically effective amount is generally about 0.01% byweight of the polymeric components. Faster rates of cure are achievedwith amounts of catalyst in the range from greater than about 0.01% toabout 5% by weight of the polymeric component. Visible light curingsystems may further comprise polymerization accelerators, which includevarious organic tertiary amines well known in the art. In visible lightcurable compositions, the tertiary amines may be acrylate derivativessuch as dimethylaminoethyl methacrylate and, particularly,diethylaminoethyl methacrylate (DEAEMA) and aromatic tertiary aminessuch as ethyl dimethylamino benzoate (EDMAB) in amounts in the rangefrom about 0.05 to about 2 weight percent, for example from about 0.1 toabout 0.5 weight percent.

Alternatively, the composition may be formulated as a self-curingsystem. Self-curing compositions will generally contain free radicalpolymerization initiators, such as a peroxide in an amount of about 0.01to about 2.0 wt % of the total resin composite material. Particularlysuitable free radical initiators include lauryl peroxide, tributylhydroperoxide, benzoyl peroxide, and cumene hydroperoxide.

Polymerization accelerators suitable for use are the various organictertiary amines well known in the art. In visible light curablecomposite materials, the tertiary amines are generally acrylatederivatives, such as dimethylaminoethyl methacrylate and, particularly,diethylaminoethyl methacrylate (DEAEMA) in an amount of about 0.05 toabout 0.5 wt % of the total composition.

In the self-curing compositions, the tertiary amines are generallyaromatic tertiary amines. For example, tertiary aromatic amines such asethyl 4-(dimethylamino)benzoate (EDMAB),2-[4-(dimethylamino)phenyl]ethanol, N,N-dimethyl-p-toluidine (DMPT), andbis(hydroxyethyl)-p-toluidine are commonly useful. Such reducing agentsare generally present in an amount of about 0.5 to about 4.0 wt % of thetotal composition. A thiourea or its derivative reducing agent may alsobe used in the compositions as taught by U.S. Pat. No. 7,275,932,assigned to Jin, et al.

The compositions may also comprise other additives and solvents known inthe art, for example, ultra-violet light absorbers; anti-oxidants suchas BHT; stabilizers; fillers; pigments; opacifiers; handlingagents/rheology modifiers; fluorescence agent; antimicrobial agents;therapeutical and/or bioactive components; mineralization promotingagent or filler; and others. For example, it is useful to employ anultraviolet absorber in an amount of about 0.05 to about 5.0 wt % of thetotal composition. Such UV absorbers are particularly desirable in thevisible light curable compositions in order to avoid discoloration ofthe resin from incident ultraviolet light. Suitable UV absorbers are thevarious benzophenones, particularly UV-5411 available from AmericanCyanamid Company; and benzotriazoles known in the art, particularly2-(2′-hydroxy-5′-methylphenyl)-benzotriazole, sold under the trademarkTINUVIN® P by Ciba-Geigy Corporation, Ardsley, N.Y.

Suitable fillers may be particulate or fibrous fillers with sizes fromnano-scales to micron-scales. Fillers conventionally used in the dentalindustry that are capable of being covalently bonded to the resin matrixitself or to a coupling agent may be included. Such fillers aredescribed in U.S. Pat. Nos. 4,544,359 and 4,547,531, the pertinentportions of which are hereby incorporated by reference. Examples ofsuitable filling materials include but are not limited to amorphoussilica; spherical silica; colloidal silica; barium glasses; quartz;ceramic fillers; silicate glass; hydroxyapatite; calcium carbonate;fluoroaluminosilicate; barium sulfate; quartz; barium silicate;strontium silicate; barium borosilicate; barium boroaluminosilicate;strontium borosilicate; strontium boroaluminosilicate; bioglass; dentalglass ionomer filler; glass fibers; lithium silicate; ammoniated calciumphosphate; deammoniated calcium phosphate; calcium tungstate; alumina;zirconia; tin oxide; zinc oxide; calcium oxide; bismuth compounds suchas bismuth oxychloride and bismuth oxide; polymer powders such aspolymethyl methacrylate, polystyrene, and polyvinyl chloride; titaniumdioxide; bound and nanostructured silica fillers as set forth incommonly owned U.S. Pat. No. 6,417,246, which is hereby incorporated byreference; densified and embrittled glass fibers or particles as setforth in commonly owned U.S. Pat. Nos. 6,013,694 and 6,403,676, whichare hereby incorporated by reference; fibrous material and one or moreforms of surface-modifying particles bonded thereto as set forth incommonly owned U.S. Pat. No. 6,270,562, which is hereby incorporated byreference; polyhedral oligomeric silsesquioxane fillers as set forth inU.S. Pat. No. 6,653,365, which is hereby incorporated by reference;nanostructures such as POSS™ (polyhedral oligomeric silsesquioxane)supplied by Hybrid Plastics; and combinations of all the fillersmentioned. Particularly suitable fillers for dental filling-typematerials prepared are those having a particle size in the range fromabout 0.01 to about 10 μm, together with a colloidal silica or fumedsilica having particle sizes in the range from about 0.001 to about 0.07μm.

A coupling agent may be used with the filler or the filler may bepretreated with a coupling agent, such as a silane coupling agent. Forexample, a commonly used coupling agent in the dental industry isγ-methacryloxypropyltrimethoxy silane.

In one particular embodiment, the composition may further include anacid-reactive filler, such as a glass ionomer (GI) filler. Contactbetween the acid functional group and the acid-reactive GI filler, inthe presence of water or moisture, facilitates a self-hardening in thedark due to an ionic reaction between the acidic group and the surfaceof the GI filler. This provides a complementary polymerization to theepoxy ring-opening and free-radical polymerizations, as discussed above.

Therefore, according to embodiment of the invention, a two-partcomposition is provided wherein the first part comprises anepoxy-containing compound, and optionally non-epoxy containing compoundswhich can be (meth)acrylates without acidic groups; and a second partcomprises a polymerizable, ethylenically-unsaturated resin having anacid functional group. The weight ratio between epoxy-containingcompound and polymerizable, ethylenically-unsaturated resin having anacid functional group can vary depending on the type of acid and epoxy,as well as the applications. In one embodiment, the range is from about1:10 to about 10:1; for example about 1:5 to about 5:1. A suitableradical polymerization initiator may be included in one or both of theaforementioned parts.

As such, a convenient procedure can be realized when the two-partpolymerizable composition is pre-packaged, such that the desired mixingratio is provided upon use. For example, a dental composition may bepackaged in a dual-syringe assembly, two individual non-joined syringes,two tubes, two capsules, one capsule where the two pastes are segregatedand do not come in contact with each other, blister packs, etc., asknown to one skilled in the art. The above are examples of pre-packagedcontainers, which provide the first part and the second part inpackaging that physically separates the first part from the second part.

The dual-syringe assembly may be fitted with a static mixer/tip so thatthe two pastes are mixed in the static mixer to result in a homogenousor a substantially homogenous composition which flows out from the tip.The dental practitioner can dispense the homogeneously mixed compositiondirectly to a dental substrate, resulting in significant time savingsand convenience in addition to improved adhesion.

This invention is illustrated by the following examples that are merelyfor the purpose of illustration and are not to be regarded as limitingthe scope of the invention or the manner in which it can be practiced.

EXAMPLES

Materials used for the following examples are set forth in Table Abelow. The recited percentage for a specific additive included in agiven resin component is a weight percentage based on the total weightof the resin component.

TABLE A Materials used in examples. Abbreviation Chemical Name ProducerUVR6110 Cyracure ™ Cycloaliphatic Dow Chemical epoxide resin Epoxy 06Cycloaliphatic epoxide resin Synasia, NJ equivalent to UVR6110 BADGEBisphenol A diglycidyl ether - Dow Chemical DER332 BFDGE Bisphenol Fdiglycidyl ether Sigma Aldrich RDGE Resorcinol digycidylether SigmaAldrich NGDGE Neopentyl glycol diglycidyl ether Sigma Aldrich 4-MET4-Methacryloxyethyl trimellitic Pentron acid HEMA 2-Hydroxyethylmethacrylate Degussa MMA Methacylic acid Sigma Aldrich BEPMABis[2-(Methacryloyloxy)-ethyl] Sigma Aldrich phosphate EGPMA Ethyleneglycol methacrylate Sigma Aldrich phosphate TEGDMA Triethyleneglycoldimethacrylate Esstech, PA R7200 Silane treated fumed silica basedDegussa Corp on Aerosil A200 GI Glass ionomer filler, 4 micronIndustrialCorporation particles BiOCl Bismuth oxychloride EngelhardCaWO₄ Calcium Tungstate Sigma Aldrich Barite Barium Sulfate SachtlebenCorp.

Example 1

Cationic Curing Test of Epoxy with Various Acidic Methacylates

For the curing tests of Example 1, the compositions utilized for theepoxy pastes (UVR6110, BFDGE/TEGDMA, BADGE/TEGDMA, RDGE and NGDGE) andthe acidic methacrylate pastes (4-MET/HEMA, MMA, BEPMA and EGPMA) areshown in Table 1. The BADGE/TEGDMA resin was prepared by mixing BADGEand TEGDMA in 90/10 weigh ratio. The 4-MET/HEMA resin was prepared bymixing 4-MET with HEMA in 67/33 weight ratio. The remaining resins (MMA,EGPMA and UVR6110) were used as received. The resin and fillers weremixed together and yielded a flowable consistency. The curing tests wereperformed at 38° C. by mixing an equivalent portion, by weight, of eachepoxy paste and each acidic methacrylate paste. By monitoring the geltimes of the curing samples, the chemical reactivity upon mixing betweenan epoxy and an acidic methacrylate resin composition was determined.(As a definition, the gel time here is the interval of time required forthe flowable resin composition to become a semisolid jelly or viscositybuild-up significantly from the original pasty consistence). The geltime is recorded in Table 2.

TABLE 1 Epoxy and acidic methacrylate paste composition. Paste ResinPaste composition E11 UVR6110 50% resin, 50% GI E12 BFDGE/TEGDMA (90/10)50% resin, 50% GI E13 BADGE/TEGDMA (90/10) 50% resin, 50% GI E14 RDGE38% resin, 62% GI E15 NGDGE 34% resin, 66% GI M11 4-MET/HEMA (67/33) 50%resin, 50% BiOCl M12 MMA 41% resin, 2% R7200, 57% BiOCl M13 BEPMA 43%resin, 2% R7200, 55% BiOCl M14 EGPMA 43% resin, 2% R7200, 55% BiOCl

TABLE 2 Epoxy and acidic methacrylate paste curing test. Curing test Geltime at RT Gel time at 38° C. E11-M11  3 hrs  1 hr E11-M12  1 hr 30 min 30 min E11-M13  10 sec  <5 sec E11-M14  10 sec  <5 sec E12-M11 >24 hrs 15 hrs E12-M12 >24 hrs >24 hrs E12-M13  2 hrs  30 min E13-M13  2 hrs 30 min E14-M13  2 hrs  30 min E15-M13  5 hrs  1 hr 30 min

Example 2

Epoxy Resin Cationic Curing Test Monitored by FTIR

Epoxy resin UVR6110 and 4-MET/HEMA/UDMA (in a weight ratio of 60/30/10)resin were mixed in 1:1 weight ratio and maintained at a temperature of38° C. while the polymerization reaction was monitored by FTIR. After 5hours at 38° C., it was observed that the composition had an increasedviscosity and the epoxy peak in the IR spectrum at 898 cm⁻¹ was observedto have decreased intensity relative to when the resins were initiallymixed. The disappearance of epoxy peak at 898 cm⁻¹, as well as thehardening of mixed resin, were observed after 24 hours of curing at 38°C., indicating the epoxide had undergone a ring-opening polymerizationin the presence of 4-MET. It could be visually determined that the curedresin had a dry surface.

Example 3

Epoxy Resin Cationic Curing and Methacrylate Free Radical Curing Test

Light initiator CQ (0.4%) and co-initiator EDMAB (1.0%) were added to asample of UVR6110 resin. Stabilizer BHT (0.02%) and peroxide BPO (2.5%)were added to a sample of 4-MET/HEMA/UDMA (in a weight ratio of60/30/10) resin. The two resins were mixed in 1:1 weight ratio and thepolymerization was monitored by FTIR. The resin hardened after 30minutes, but the surface remained wet at that time. The observed fasterrate of hardening of the resin mixture, as compared to Example 2,indicates that the methacrylate free radical polymerization occurredbefore the epoxide ring-opening polymerization. The surface layerdemonstrated a curing behavior similar to Example 2, however. Asubsequent FTIR scan of the surfaced layer was conducted at 5 hours and24 hours after the cure and showed a similar disappearance of the epoxypeak at 898 cm⁻¹, as in Example 2.

Example 4

Paste-Paste Epoxy Cationic Curing and Methacrylate Free Radical CuringTest

Each resin in Example 2 and Example 3 was mixed with fillers to obtain aflowable consistency. The paste compositions are listed in Table 3. Thecuring test was performed by mixing 1:1 weight ratio of epoxy paste andmethacrylate paste. Gel time was tested at both room temperature and 38°C. The test results were shown in Table 4.

TABLE 3 Epoxy and methacrylate paste composition. Paste Resin Pastecomposition E41 UVR6110 in Example 2 47% resin, 1% R7200, 15% GI, 25%BiOCl, 12% Ca₃(PO₄)₃ E42 UVR6110 in Example 3 47% resin, 1% R7200, 15%GI, (contains CQ & EDMAB) 25% BiOC, 12% Ca₃(PO₄)₃ M41 4-MET/HEMA/UDMA49.5% resin, 0.5% R7200, 60/30/10 in Example 2 50% BiOCl M424-MET/HEMA/UDMA 49.5% resin, 0.5% R7200, 60/30/10 in Example 3 50% BiOCl

TABLE 4 Epoxy and methacrylate paste curing test. Curing test Gel timeat RT Gel time at 38° C. E41-M41 24 hr 12 hr E42-M42  2 hr 40 min

A significantly faster curing rate was observed for theepoxy/methacrylate composition containing the peroxide free radicalpolymerization initiator, as shown in Table 4. Moreover, the E42-M42system is also light curable. The dual cure (light and self-curable)nature and working time is suitable for root canal sealant applications.

Example 5

Property Test of Cured Epoxy/Methacrylate Compositions as Root CanalSealant

The epoxy paste E42 and acidic methacrylate paste M42 were mixed in 1:1weight ratio and the properties were tested and summarized in Table 5.The surface residue monomer of the cured paste was evaluated bymeasuring the removable/wipable surface residue monomer amount. Thecatalyst and base paste, 0.25 g each, were mixed and the resultant pastewas applied as a film to a glass slide without covering the film. Thepaste was spread on the glass slide in a way that the film thickness ofthe paste varied from approximately 0.1mm to 1.0 mm After the pastegelled at room temperature, it was placed under different conditions: 1)room temperature for over 24 hours, 2) 37° C. for over 12 hours withoutmoisture, 3) 37° C. for over 24 hours with 100% humidity. The glassslide, which included the cured sealer material, was first weighed toobtain an original weight, then the surface of the cured sealer materialwas wiped with lint free Kimwipes®. The glass slide was weighed again toobtain a final weight. The residue monomer % value was calculated as theweight percent difference of the final weight and the original weight.

For physical properties evaluation, the pastes were mixed and set at 37°C. for 24 hours, and then stored at 37° C. in water for 24 hours for theflexural strength (FS) testing and 1 week for water absorption (WA) andwater solubility (WS) testing in reference to ISO 4049(Dentistry—Polymer-based filling, restorative and luting materials)method for the sample dimensions and sizes.

TABLE 5 Summary of cured epoxy/methacrylate compositions as root canalsealant. Property tested Property value Residue monomer % RT over 24 hrs0 37° C. over 12 hrs no moisture 0 37° C. over 12 hrs 100% humidity 0 FS(MPa) 51 WA (μg/mm³/week) 52 WS (μg/mm³/week) 0

Two commercial epoxy resin-based root canal sealers (AH Plus Jet® and AHPlus® Silver free); one commercial acid-containing methacrylate resinbased root canal sealant (Epiphany® SE); and one self-etching (SE) rootcanal sealant (RCS) composition according to an embodiment of thepresent invention (“Exp. SE RCS”) were tested for dimensional change and24 hours' solubility according to ADA/ANSI Specification No. 57“Endodontic Sealing Material”. A comparison of the results is shownbelow in Table 6.

TABLE 6 Water solubility and expansion. Material Manufacturer Lot#Expansion¹ % Solubility² Exp. SE Pentron Experimental 1.00 0.003 RCSClinical Tech. AH Plus Jet Dentsply 0801000301 0.64 0.01 AH 26 SilverDentsply 0710000944 3.2 0.08 Free Epiphany SE Pentron 163647 3.5 0.13Clinical Technologies ¹Expansion is the linear percentage change after30 days in distilled water. ²Weight percent soluble in distilled waterafter 24 hours.

Example 6

Self-Adhering Root Canal Sealant Tooth Bonding Test

Bonding strength of the Exp. SE RCS composition to dentin was comparedto a self-etch sealant (Epiphany® SE); an acid-containing methacylateresin-based self-etch root canal sealant (Pentron Corp.); and anepoxy-amine based root canal sealer material (AH Plus® Jet), which ispackaged in a double barrel dental syringe like the Epiphany® SE. Sixrods (3 mm in diameter, 6 mm height cylinder) were made using each ofthe materials being tested. Similar to a conventional dentin bondingtest, coronal dentin surface was exposed and ground first (n=6). Thedentin surfaces were subjected to a standard endodontic cleaningprocedure using 5% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacid (EDTA) solutions sequentially (Epiphany Instruction of Use,Pentron Corp.). The rods were then applied and adhered onto the dentinsurface using the corresponding sealer as the cement there between therod and dentin surface under a pressure load of a 500 gram weight on topof the composite rod. The excess sealer was removed using a spatula. Thesealant was first light cured for 30 seconds from two sides of thecomposite rod and then removed from load and further self-cured (allowto stand on bench) for 30 minutes before transferring into a containerwith 100% humidity in a 37° C. oven for 48 hours. Because AH Plus Jet®material is epoxy-amine chemically-cured and the working and settingtimes are much longer, the bonding samples were allowed to set on benchunder the 500 gram load for at least 24 hours before transferring to the37° C. oven. Bonding strengths were then tested by breaking thecomposite rod off the dentin surface using an ATS Universal TestingMachine with a push-shear direction. The load was then recorded and thebonding strength was calculated using the load divided by the surfacearea of the rod adhering to the dentin surface. The test results areshown in Table 7 below. As can be seen, the bonding strength to dentinof the Exp. SE RCS of the invention is unexpectedly much better over thecurrent commercially available Epiphany® SE sealant and the AH Plus Jet®epoxy-based sealer.

TABLE 7 Bonding strength of self-etch/self adhering root canal sealanton dentin surface. Sealant Epiphany SE² Exp. SE RCS AH Plus Jet³ Bondingstrength¹ (MPa) 2.4 (1.0) 6.3 (2.5) 0.39 (0.1) ¹Bonding strength toDentin (MPa) ²Lot# 162744 ³Lot# 0801000301

As can be seen from the data in Table 7, the bonding strength of theExp. SE RCS demonstrates about a 2.5 times increase in bonding strength,as compared to the methacrylate resin based composition with acidicmethacrylate monomer (Epiphany® SE), and about a 16 times increase overthat of an epoxy resin-based composition using epoxy-amine root canalsealer (AH Plus Jet®). The Exp. SE RCS, as formulated, can therefore beused as a root canal filling material, either alone or in combinationwith a conventional root canal filling material such as a Gutta Perchacone, a RealSeal point made from Resilon™ material, a carrier basedpoint such as ThermaFil™ (product of Dentsply) or RealSeal 1™ (productof SybronEndo), in a dental root canal treatment procedure.

Example 7

Property Test of Another Experimental Self-Etching Root Canal Sealer (SERCS).

In this example, Epoxy 06 was used as replacement of UVR6110 because Dowdiscontinued the chemical supply. Radio-opacifier filler calciumtungstate and barium sulfate were used to replace bismuth oxychloride.The formulation of this experimental self-etch root canal sealer isshown in Tables 7a and 7b.

TABLE 7a Catalyst paste formulation. Catalyst paste composition Catalystpaste composition (wt %) 4-META 27 HEMA 13.5 UDMA 4.5 BHT 0.09 BPO 1.11Silane-treated barium glass filler 25.8 Barite 28

TABLE 7b Base paste formulation. Base paste composition Base pastecomposition (wt %) Epoxy 06 28.45 CQ 0.15 EDMAB 0.3 DHEPT 0.05 Y#8087pigment 0.05 Silane-treated fumed silica 2 Barite 9 Calcium Tungstate 52GI 8

Properties were tested on this experimental SE RCS. The residue monomer%, FS, expansion and solubility tests were performed as describe inExample 5. Bonding strength test was performed as described in Example6. The properties are summarized in Table 8.

TABLE 8 Property summary of experimental SE RCS. Property testedProperty value Residue monomer % RT over 24 hrs 0 37° C. over 12 hrs nomoisture 0 37° C. over 12 hrs 100% humidity 0 FS (MPa) 41 (4)  Expansion(%)   2.63 Water Solubility (%)   0.08 Bonding strength to dentin (MPa)6.03 (2.77)

While the present invention has been illustrated by the description ofone or more embodiments thereof, and while the embodiments have beendescribed in considerable detail, they are not intended to restrict orin any way limit the scope of the appended claims to such detail. Forexample, dental applications have been described for embodiments of theinvention, but other non-dental applications may likewise benefit fromthe inventive composition. Additional advantages and modifications willreadily appear to those skilled in the art. The invention in its broaderaspects is therefore not limited to the specific details, representativeproduct and method and illustrative examples shown and described.Accordingly, departures may be made from such details without departingfrom the scope of the general inventive concept.

1-22. (canceled)
 23. A polymerizable composition comprising: a firstpart comprising an epoxy compound and an acid-reactive filler; and asecond part comprising a polymerizable, ethylenically-unsaturated resinhaving an acid functional group, wherein the acid functional group is acarboxylic acid, a carboxylic acid anhydride, an acyl halide, a sulfonicacid, a sulfonic anhydride, a sulfonyl halide, a sulfinic acid, asulfinic anhydride, a sulfinyl halide, a phosphoric acid, a phosphoricacid derivative, a phosphonic acid, or a phosphonic acid derivative,wherein the first part and/or the second part further comprises aradical initiator.
 24. The polymerizable composition of claim 23 whereinthe first part further comprises a non-epoxy-containing polymerizablecompound having no acid functional group.
 25. The polymerizablecomposition of claim 23 wherein the first part comprises the radicalinitiator.
 26. The polymerizable composition of claim 23 wherein theradical initiator comprises a photo-initiator.
 27. The polymerizablecomposition of claim 26 wherein the radical initiator further comprisesa tertiary amine polymerization accelerator.
 28. The polymerizablecomposition of claim 23 wherein the radical initiator comprises areducing agent and an oxidizing agent.
 29. The polymerizable compositionof claim 23 wherein the second part further comprises anon-epoxy-containing polymerizable compound having no acid functionalgroup.
 30. The polymerizable composition of claim 23, wherein thepolymerizable, ethylenically-unsaturated resin having an acid functionalgroup is acrylic acid, methacrylic acid, 2-(methacryloyloxy)ethylphosphate, bis(2-(methacryloyloxy)ethyl)phosphate, biphenyldimethacrylate, ethylene glycol methacrylate phosphate,4-methacryloxyethyl trimellitic anhydride, 4-methacryloxyethyltrimellitic acid, adduct reaction product of pyromellitic di-anhydridewith 2-hydroxyethylmethacrylate, adduct reaction product of pyromelliticdi-anhydride with glycerol dimethacrylate, or adduct reaction product ofbenzenetetracarboxylic acid di-anhydride with2-(6-hydroxy-1-oxo-hexyloxy)ethyl methacrylate.
 31. The polymerizablecomposition of claim 23, wherein the polymerizable,ethylenically-unsaturated resin having an acid functional group is anethylenically unsaturated phosphoric acid ester having the generalformula:(CH₂═C(CH₃)CO₂—R—O)_(n)P(O)(OH)_(3-n) wherein R is a substituted orunsubstituted alkyl or aryl group having about 1 to about 36 carbonatoms and n equals 1 or
 2. 32. The polymerizable composition of claim 23wherein the epoxy compound is a monomeric or a polymeric aliphatic,cycloaliphatic, aromatic or heterocyclic epoxide.
 33. The polymerizablecomposition of claim 23, wherein the composition is a dental fillingmaterial that is adapted to bond to dentin.
 34. A method of providing apolymerizable composition comprising: providing a first part comprisingan epoxy compound and an acid-reactive filler; and providing a secondpart comprising a polymerizable, ethylenically-unsaturated resin havingan acid functional group selected from a carboxylic acid, a carboxylicacid anhydride, an acyl halide, a sulfonic acid, a sulfonic anhydride, asulfonyl halide, a sulfinic acid, a sulfinic anhydride, a sulfinylhalide, a phosphoric acid, a phosphoric acid derivative, a phosphonicacid, or a phosphonic acid derivative, wherein the first and/or secondpart further comprises a radical initiator, whereby upon mixing thefirst part and the second part the acid functional group is adapted toinitiate a cationic polymerization of the epoxy compound; and whereinthe radical initiator is adapted to initiate a free-radicalpolymerization of the polymerizable, ethylenically-unsaturated resin.35. The method of claim 34, wherein the polymerizable,ethylenically-unsaturated resin having an acid functional group isacrylic acid, methacrylic acid, 2-(methacryloyloxy)ethyl phosphate,bis(2-(methacryloyloxy)ethyl)phosphate, biphenyl dimethacrylate,ethylene glycol methacrylate phosphate, 4-methacryloxyethyl trimelliticanhydride, 4-methacryloxyethyl trimellitic acid, adduct reaction productof pyromellitic di-anhydride with 2-hydroxyethylmethacrylate, adductreaction product of pyromellitic di-anhydride with glyceroldimethacrylate, or adduct reaction product of benzenetetracarboxylicacid di-anhydride with 2-(6-hydroxy-1-oxo-hexyloxy)ethyl methacrylate.36. The method of claim 34, wherein the polymerizable,ethylenically-unsaturated resin having an acid functional group is anethylenically unsaturated phosphoric acid ester having the generalformula:(CH₂═C(CH₃)CO₂—R—O)_(n)P(O)(OH)_(3-n) wherein R is a substituted orunsubstituted alkyl or aryl group having about 1 to about 36 carbonatoms and n equals 1 or
 2. 37. The method of claim 34 wherein the firstpart comprises the radical initiator.
 38. The method of claim 34 whereinthe radical initiator comprises a photo-initiator.
 39. The method ofclaim 38 wherein the radical initiator further comprises a tertiaryamine polymerization accelerator.
 40. The method of claim 34 wherein theradical initiator comprises a reducing agent and an oxidizing agent. 41.A kit comprising: the polymerizable composition of claim 23, wherein thefirst part and the second part are provided in packaging that physicallyseparates the first part from the second part; and instructions formixing to effect a self-cure.
 42. The kit of claim 41, wherein theradical initiator is a photo-initiator and a tertiary aminepolymerization accelerator, and wherein the instructions further includea light cure step.